Electric clutch-brake driving devices



Oct. 28, 1958 E. P. TURNER ETAL 2,857,996

ELECTRIC CLUTCH-BRAKE DRIVING DEVICES Filed Jan. s, 1956 2 Sheets-Sheet1 //vv/vr0/?s Edgar P. Turner and Lorenz A. Wendel WITNESS TOR/VEX Oct.28, 1958 E. P. TURNER ETAL 5 ELECTRIC CLUTCH-BRAKE DRIVING DEVICES FiledJan. 3, 1956 2 Sheets-Sheet 2 u, """IIIIIII //v VENTORS Edgar R Turnerand Lorenz A. Wendel B) IZTOR/VEY ELECTRIC CLUTCH-BRAKE DRIVING DEVICESEdgar P. Turner, Watchung, and Lorenz A. Wendel,

Somerville, N. .L, assignors to The Singer Manufacturing Company,Elizabeth, N. J., a corporation of New Jersey Application January 3,1956, Serial No. 557,045

Claims. (Cl. 192-18) This invention relates to electric power drivingdevices for operating sewing machines or the "like and more particularlyto means for supporting the driving device on the structure carrying themachine to be driven.

The driving devices to which the present invention relates are known inthe art as electric power transmitters and generally comprise a housingor casing containing an electric driving motor, a clutch-brake mechanismand having exterior of the housing a driving pulley operativelyconnected to the driving unit and a depending actuating lever forselectively actuating or braking the driving pulley. The powertransmitter is normally mounted on the underside of a table topsupporting the.

machine to be driven with the driving pulley of the transmitter in beltdriving alignment with the driven machine pulley.

It is an object of the present invention to provide a power transmittersupporting structure which is simple in construction and economical toproduce.

It is a further object to provide a novel supporting structure whichpermits adjustment of the belt tension between the driving and drivenpulleys.

In connection with the adjustment of the belt tension, the transmitteris relocated away from or toward the support carrying the driven machineand under some circumstances the actuating lever may be inconvenientlypositioned relatively to the pedal actuating linkage associatedtherewith, and may result in improper transmitter operation.

It is accordingly a further object to provide a means for maintainingthe desired actuating lever and pedal actuating position independentlyof the desired belt tensioning position of the transmitter.

Briefly, the objects of the present invention are accomplished bymounting the power transmitter on a supporting bracket constructed topermit movement about a pivot toward and away from the table topcarrying the driven machine, thereby to obtain the desired belttensioning relationship between the transmitter and driven pulley andalso by providing an enclosing shroud for the transmitter which issecured thereto in a manner to permit relative axial turning of thetransmitter frame whereby the actuating lever appended to thetransmitter may be selectively positioned.

In the drawings, Fig. 1 is a front elevational view of a powertransmitter attached to a table top by the supporting structure of thepresent invention.

Fig. 2 is a sectional view of the power transmitter and the supporttaken along the lines 2-2 of Fig. 1.

Fig. 3 is a sectional view of the power transmitter and support takenalong the lines 3-3 of Fig. 1 with the details of the interior of thetransmitter omitted and showing alternative belt tightening positions ofthe transmitter.

Referring more specifically to the drawings the electric powertransmitter is shown having a casing 11 comprising a cylindrical frame12 enclosed at one end by a a cap member 13. Extending from the otherend and enclosing the same is an end enclosure bell 14 of a motor 15.Radially projecting from the exterior of the motor frame are a pluralityof longitudinal cooling ribs 16 which form a portion of the cylindricalframe 12. For a more detailed description of the transmitter assemblyreference may be had to the copending application of Ross D. Ingalls,Serial No. 285,441, filed on May 1, 1952, now Patent No. 2,739,251.

Disposed within the casing 11 adjacent the end cap 13 is theclutch-brake mechanism arranged and constructed in a manner similar tothat shown in the above.

mentioned application. Axially projecting from a central apertureprovided in the end cap 13 is a pulley shaft 19' having fixedly securedthereto a grooved pulley 20 adapted to receive a continuous belt 21 todrive a sewing machine (not shown) mounted on the table top 22.

The clutch-brake mechanism is controlled by an L- shaped actuating lever23 which is pivotally supported on a pin 24 carried by a pair of spacedbosses 25 formed on the end cap 13. A yoke 26 is provided on one end ofthe lever and carries a control pin 27 which extends through a slidingcollar 28 having attached thereto, within the housing, a movable clutchmember (not shown) which is selectively engageable with either a drivenflywheel or a brake to control rotational movement of the driving pulley20 as explained in the aforementioned copending application.

The other end of the actuating lever 23 has an outwardly projectingL-shaped bracket 29 having attached thereto a pivot member 30substantially parallel with the lever 23. The pivot member 30 terminatesin a ball 31 which seats within the spherical opening 32 provided on oneend of a pedal-actuated link which at its other end is adjustablyconnected by a clamp 34 to a link 35 which is connected to a foottreadle 36.

By the present invention the transmitter casing is provided with a novelenclosing shroud 37 which is constructed and mounted on the frame 11 ofthe transmitter in a manner to permit limited axial turning of thetransmitter about its longitudinal axis and also to provide forattaching the power transmitter 10 on a supporting bracket 46 for bodilyarcuate movement about a pivot toward and away from the table top.

As shown, the shroud 37 is a split-cylinder made of sheet metal and hasoverlapping portions. The upper overlapping portion is formed with atongue 38 which extends between spaced projecting clamping; lugs 39fixedly secured to the shroud by welding or the like. Also secured tothe shroud by welding are spaced straps 40 terminating in upstandingclamping lugs. 41 adjacent the edge of the upper overlapping portion ofthe shroud 10 and in alignment with the lugs 39.

The shroud 37 is slidably fitted over the cylindrical frame 11 andengages the outer periphery of the radial ribs 16. The frame is held ina fixed position within the shroud by tightening the screws 42 passingthrough openings 43 in each of the lugs 39 and the respective alignedthreaded openings 44 in the lugs 41 to draw the lugs 39 and 40 togetheragainst the action of spring 45 disposed around the screw between thelugs until the shroud is clamped against the cylindrical frame 11including the ribs 16 of themoto-r 15.

The power transmitter is mounted on the underside of a table top 22 by asupporting bracket 46 secured to the table top by bolts 47 and nuts 48.The bracket comprises a mounting plate 49 formed with a flat horizontalportion 50, adapted to rest flush against the underside of the tabletop, and a depending inclined portion 51.

The plate is also formed with downwardly depending side are providedadjacent the lower edge. 7 of the inclined portion 51,

Patented Oct. as, 1958- ings'53 in which a horizontal hollow supportingtube 54-issecured preferably with a force fit.

In a transmitter support, it is frequently necessary to adjust the belttightness on the driving pulley in order to maintain the desired drivingrelationship with the sewing machine pulley and it is desirable thatthis be accomplished with the minimum amount of elfort andinconvenience. By the present invention this is accomplished byattachingthe transmitter to the supporting bracket 46 for pivotal movement aboutthe supporting tube 54, whereby the transmitter including the drivingpulley 20 is swingable in an arc toward and away from the table top 22.As shown, each of thestraps 40 secured to the shroud 38 extendtangentially therefrom and is formed with a curved end portion 55adapted to partially encircle the tube '54. Associated with each strap40 is a clamping plate 56 secured thereto by a stud 57, each strapadjacent its free end being formed with a curved portion 58substantially complemental to the curved portion 55 of the strap 40 toform therewith a tube engaging clamp. In order to maintain the straps 40tangential with the shroud there are provided braces 59 which arefixedly secured at one end to the strap 40 and the other end to theshroud 37 by welding or the like.

To assure that the transmitter 10 maintains'its desired angular positionabout the supporting rod 54 a novel adjustable link connection isprovided between the bracket and thetransrnitter. As shown, this linkconnection-comprises a split sheet-metal band 60 which encircles theshroud between the straps 40. One end of the band is formed with a pairof spaced ears 61 which carry a pin 62 having a central opening throughwhich a screw 63 passes. Spaced from the edge of the other end of theband and fixedly secured thereto is a projecting lug 64 having athreaded opening adapted to receive the screw 63. Encircling the screw63 between the lug 64 and pin 62 is a compression spring 65. In order tomaintain the band fixed on the transmitter it is apparent that it isonly necessary to tighten the screw 63 and thereby draw the band tightagainst the outer surface of the shroud 37 which has previously beenclamped on the cylindrical frame 11.

Pivotally connected to the pin 62 is one end of curved H.-shaped link 66which at its other end is pivotally mounted on a stud 67 secured in asubstantially -U- shaped bracket 68, the latter being secured adjacentthe free edge of the horizontal portion of the bracket by a rivet or thelike.

From the foregoing description it is apparent that the tightening of thebelt on the driving pulley with the mounting structure of the presentinvention has many advantages.

In .the event it is desired to change the tightness or tension of thebelt the transmitter is moved toward or away from the driven machinesupport 22 as shown in Fig. 3, wherein the dotted and full lines showtwo alternative positions of the transmitter. To obtain the desired beltadjustment, the band 60 encircling the transmitter is unclarnped byloosening the screw 63 whereupon the compression 65 spring functions toopen the band. With the band 60 opened the band and the transmitter maybe rotated relatively to each other and the transmitter may be swung upor down, about the supporting tube 54 within the limits of the length ofthe link 66 until the desired belttension is obtained. During therelative turning of the band and transmitter, and the swinging of thelatter about the tube54, the pivot pin 62 on the band 60,:carrying oneend of the, link 66 swings arcuately with thetransmitter and also :movescircularly with the band 60 about the transmitter toward or away fromthe fixed pivot stud .67 c'arryingthe other end of the link 66. Sincethe link 66 is of fixed length, when the band 60 is tightened andclamped on the shroud 38 of the transmitter which is located in its newbelt tightening position, the

When the belt tension is adjusted in the above manner,

that is by swinging the transmitter about the tube 54, the lever movesout of the substantial vertical plane shown in Fig. 2. Under somecircumstances this may be undesirable since the relocation may, forinstance, cause interferencewithother mechanisms mounted on the.underside of the table or may cause the treadle actuating links 34 and35 to bind, resulting in improper transmitter .operation. By the presentinvention the shroud 38 is split as above described and When the screws42 are loosened the springs 45 between the lugs 39 and 40 tend toenlarge the shroud .thereby to permit limited turning of the transmitterframe including the actuating lever until the latter is again in thesubstantially vertical plane. It is, of course, to be understood that inorder to enlarge the opening of the shroud 37 to permit turning of thetransmitter frame the band will also be opened. Thereafter the shroud istightened against the transmitter frame and the *band 60 is clamped onthe shroud 37 as described above.

Having thus set .forth the nature of the invention, what we claim hereinis:

1. 'The combination of a power driving unit having an actuating leverand mean-s for adjustably mounting thedriving unit on the structurecarrying the machine to be driven; said driving unit having asubstantially cylindrical casing including a longitudinal axis; a splitband adapted to encircle slidably said casing and having a pivot memberfixedly secured thereto, said band having means for clamping said bandon said casing to secure said band on said casing selectively toposition angularly said pivot member relatively to said driving unitaxis; said mounting means including pivot means parallel with saiddriving unit axis; means connecting said unit to said pivotal mountingmeans for swinging said driving unit about said mounting pivot meanstowards and away from the machine to be driven; and a link pivotallymounted at one end to said mounting means and at its other end to saidband pivot member to position angularly said driving unit relatively tosaid mounting pivot means when said band pivot member is selectivelypositioned.

,2. The-combination of a power driving unit having an actuating leverand means for adjustably mounting the driving unit on the structurecarrying the machine to be driven; said driving unit comprising asubstantially cylindrical frame having a longitudinal axis and includingan encircling shroud clamped on said frame; a split band adapted toencircle slidably said shroud, said band having a pivot member fixedlysecured thereto and means for clamping said band on said shroudselectively to position said band pivot member on said encirclingshroud; said mounting means including pivot means parallel with saiddriving unit axis; means connecting said unit to said pivotal mountingmeans for swinging the driving unit aboutsaid mounting pivot meanstowards and away from the machine to be driven; and a link pivotallymounted at one end to said mounting means and at its other end to saidband pivot member whereby said driving unit is angularly positionedrelative to said mounting pivot means when said band pivot isselectively positioned.

3. The combination of a power driving unit having an actuatinglever anda supporting bracket for adjustably mounting the driving unit on thesupport structure carrying the machine to be driven; said driving unitcomprising a substantially cylindrical frame having a longitudinal axis;a splitshroud adapted to encircle slidably said frame whereby said framemay be turned about its longitudinal axis in said shroud; means forconstricting said shroud to clamp said frame therein thereby to maintainsaid actuating lever in a selective plane; said supporting bracketincluding driving unit pivot means substantially parallel with saidframe axis and means including adjustable means operatively connected tosaid shroud and said bracket for maintaining said driving unit angularlypositioned on said bracket pivot means.

4. The combination of a power driving unit having an actuating lever anda supporting bracket for adjustably mounting the driving unit on thesupport structure carrying the machine to be driven; said driving unitbeing mounted for movement toward and away from the support structureand comprising a substantially cylindrical frame, a split enclosingshroud slidably encircling said frame whereby said frame may be turnedabout its longitudinal axis in said shroud, means for constricting saidshroud to clamp said frame therein thereby to maintain said actuatinglever in a selective plane, said supporting bracket having driving unitpivot means substantially parallel with the frame axis, driving unitmounting means swingably supported on said driving unit pivot means andconnected to said shroud, link pivot means operatively connected to saidshroud and adjustably turnable about said frame axis, and a linkpivotally connected at one end to said bracket and at its other end tosaid link pivot means for maintaining said driving unit angularlypositioned on said driving unit pivot means.

5. The combination of a power driving unit having an actuating lever anda supporting bracket for adustably mounting the driving unit on thesupport structure carrying the machine to be driven; said driving unitcomprising a substantially cylindrical frame including a longitudinalaxis; a split enclosing shroud adapted to encircle 6 slidably said framewhereby said frame may be turned in said shroud; means for constrictingsaid shroud to clamp said power unit therein thereby to maintain saidactuating lever in a selective plane; said supporting bracket havingdriving unit pivot means substantially parallel with said frame axis;driving unit mounting means swingably supported on said driving unitpivot means and connected to said shroud; a split band adapted toencircle slidably said shroud, said band having a link pivot meansfixedly secured thereto; means for clamping said band on said shroud toposition angularly said link pivot means relative to said frame axis;and a link pivotally connected at one end to said adjustable link pivotmeans and at its other end to said bracket for maintaining said drivingunit angularly positioned on said driving unit pivot means when saidpivot band member is selectively positioned.

References Cited in the file of this patent UNITED STATES PATENTS1,282,198 Davis Oct. 22, 1918 2,680,504 Schweda June 8, 1954 2,702,106Strahota et al Feb. 15, 1955 2,703,369 Voigt Mar. 1, 1955 FOREIGNPATENTS 75,148 Denmark Dec. 15, 1952

